Mixing Up Matter

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Objective

SWBAT distinguish between a heterogeneous and homogeneous mixture by creating models that represent each one.

Big Idea

Students will conduct an investigation to find ways to separate different mixtures.

Lesson Overview

5e Lesson Plan Model

Many of my science lessons are based upon and taught using the 5E lesson plan model: Engage, Explore, Explain, Elaborate, and Evaluate. This lesson plan model allows me to incorporate a variety of learning opportunities and strategies for students.  With multiple learning experiences, students can gain new ideas, demonstrate thinking, draw conclusions, develop critical thinking skills, and interact with peers through discussions and hands-on activities.  With each stage in this lesson model, I select strategies that will serve students best for the concepts and content being delivered to them.  These strategies were selected for this lesson to facilitate peer discussions, participation in a group activity, reflective learning practices, and accountability for learning.

Lesson Synopsis 

The Mixtures and Solution in matter lesson takes one class period. Students activate their prior knowledge in a quick write activity that asks them to share what they think the terms mixture and solution mean. We use their ideas to engage in a discussion and accurately define each word. Then students investigate two kinds of mixtures-heterogeneous and homogeneous by creating three different models. The keep track of their observations on a data table and use it to find ways to separate the mixtures they created. The lesson ends with students reflecting on what they have learned by filling out a 3-2-1 exit ticket.

Next Generation Science Standards  

This lesson will address the following NGSS Standard(s): 

PS 1-1 Develop a model to describe that matter is to small to be seen. 

PS 1-3 Make observations and measurements to identify materials based on their materials.

Scientific & Engineering Practices

Students are engaged in the following Scientific and Engineering Practices:

2.) Developing and Using Models- Students create three different models of mixtures to determine which ones are heterogeneous and homogeneous. 

3.) Plan and Conduct and Investigation-Students investigate ways to separate three different mixtures using materials like filters, strainers, heat, etc.  

Crosscutting Concepts

The Mixtures and Solutions Matter lesson will correlate to other interdisciplinary areas.  These Crosscutting Concepts include:

6.) Structure and Function-  Students use three different models with substances of different properties to identify how some materials mix homogeneously and others heterogeneously. They observe how certain materials combine and other do not. The examine how these mixtures can be separated. 

Disciplinary Core Ideas

Disciplinary Core Ideas within this lesson include:

PS1.A Structure of Matter:  Matter of any type can be subdivided into particles that are too small to see, but even then the matter still exists and can be detected by other means.  A model showing that gases are made from the matter of particles that are too small to see and are moving freely around in space can explain many observations.

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Classroom Management Considerations

Importance of Modeling to Develop Student Responsibility, Accountability, and Independence 

Depending upon the time of year, this lesson is taught, teachers should consider modeling how groups should work together; establish group norms for activities, class discussions, and partner talks.  In addition, it is important to model think aloud strategies.  This sets up students to be more expressive and develop thinking skills during an activity.  The first half of the year, I model what group work and/or talks “look like and sound like.”  I intervene the moment students are off task with reminders and redirecting.  By the second and last half of the year, I am able to ask students, “Who can give of three reminders for group activities to be successful?” Who can tell us two reminders for partner talks?”  Students take responsibility for becoming successful learners.  Again before teaching this lesson, consider the time of year, it may be necessary to do a lot of front loading to get students to eventually become more independent and transition through the lessons in a timely manner.

  • EXPLORE TEAMS (Pre-Set)

For time management purposes, I use “lab rats roles” I introduce these roles this at the beginning of the year. I model each role and provide students' opportunities to practice each role with a group during an investigation or lab.  It has proven successful within my classroom keeping students engaged and on task.

Each student has a number on the back of his or her chair, 1,2,3,4 (students sit in groups of 4)and displayed on the board.  For each explore activity, I switch up the roles randomly so students are experiencing different task responsibilities which include: Director, Materials Manager, Reporter, and Technician.  It makes for smooth transitions and efficiency for set up, work, and clean-up. 

Engage

12 minutes

Making a Real World Connection

I introduce this lesson by asking students: "Think of some products that you use almost every day that are made up of more than one substance?"  I call on students to share ideas out loud with their classmates.  By asking this question, I am engaging my students to think of items they use frequently use. My students respond with ideas like kool-aid, cereal, salad, and soup. One student stated laundry, which indicated this student is familiar with other examples besides edible ones. 

Then I bring students' attention to the board for the powerpoint slide question: "What is the difference between a mixture and solution?"

Using the quick write strategy, I tell the students to write a response to the displayed question. While they write, I walk around the room monitoring students. When they finish, I direct students to their elbow partner for a turn and talk using our turn and talk norms. During this time I am walking around listening to conversations about the repsonsesAt the end of turn and talk, the class reconvenes as a whole for a discussion. I use the quick pick bucket to call upon several students to share out to the class. 

 quick write responses about mixture quick write responses

 With the whole class, I continue the powerpoint and display several images of mixture and solution examples. I call on students to identify each as either a mixture or solution, based on what they think they about these terms. As students state what they believe each one is, I ask them to justify why they named it a mixture or solution. At the end of the powerpoint, I define the terms mixture and solution

  • mixture: When two or more kinds of matter are put together; each kind of matter keeps its own physical properties and can be easily separated.

 

  • solution:  a mixture where one of the substances dissolves in the other, you cannot see the parts that were combined.

 

I have them record each term in their interactive notebook and tell them they are going to learn about their similarities and differences.

 

Explore

25 minutes

Prepare to Investigate

After sharing our quick write responses, I ask a student to read the standards board aloud to the class: "Today, we will investigate mixtures and solutions to distinguish between them and learn about separating them based on their properties"

I move on and explain the task with the class and identify the lab rats roles for each part. "In your lab rats groups, you're working together to create three different models." I point out the materials on the tray each group is receiving: a container of salt, sand, koo-laid powder, rice, seeds, water, oil, and iron powder. I review each item on the tray but identify this iron powder as an unknown substance. I do this because in the second half of this lesson, I want students to figure ways to separate the mixtures and solutions and think about properties of matter that will help them do this. 

Investigation

Once each group receives the materials tray. I instruct them to place a chart in their interactive notebook, listing the ingredients on the tray. I have them note the physical properties of each one. After some time we reconvene and share them aloud. I listen for them to use properties we have been studying throughout this unit.

Next, they make predictions about what will happen when they combine the materials to create three different models in the following way:

  • Container #1- add a teaspoon of salt, a tablespoon rice, 3 tablespoons of seeds, a tablespoon of iron fillings (students do not know this yet, I simply tell them it is an unknown substance.)
  • Container #2- add two cups of vegetable oil, 1 cup of water, 5 drops of food coloring, and 1/2 alka seltzer tablet. (we add the alka seltzer to see the water move separately from the oil.
  • Container #3- add one cup of water and 3 teaspoons of koolaid powder.

 

They create each model and observe the physical properties as the materials combine. They record these observations in their notebook. 

Sharing our Observations 

I reconvene the class as a whole to share observations and engage in discussion. Our discussion is centered around questions like:

  • What did you notice happen?
  • What changed? How?
  • What stayed the same?
  • Did any appear to disappear?

 

Students share that container 1 ingredients just got mixed up. The noted that all the ingredients were a solid and you could still see each one. They shared that they could pull them out one by one if they had too. For container 2, they observed the ingredients reacting differently than in container 1. They shared that all the ingredients were a liquid and that they could see each one. Then we discussed observations about Container #3. They noticed the kool-aid power looked like it disappeared because its powder form was no longer powder. They said they knew it was still there, because the water turned the color of the kool-aid. 

I move on and ask students, "Now make an inference. Which container do you think is a mixture or solution? Write what you think in the Infer section of your chart in your notebook. 

I have students share their inferences among their groups. Then I take volunteers to share some out loud before moving on to explain more about mixtures and solutions.

 

Explain

15 minutes

Defining Mixture

Once we have set up our three different models, I direct students attention to the Studyjams video on Mixtures  displayed on the board.  This video gives an animated explanation of types of mixtures.

  • mixture: When two or more kinds of matter are put together; each kind of matter keeps its own physical properties and can be easily separated
  • heterogenous mixture: a mixture of substances that can be viewed separately. They do not blend with one another and keep their physical identities. 
  • solution:  a mixture where one of the substances dissolves in the other, you cannot see the parts that were combined.
  • homogenous mixture: a mixture that is the same throughout, so you cannot see the substances separately; these are known as solutions

 

Reading to Reinforce the Concept

After viewing the video, I hand out a reading passage to further define the types of mixtures. This passage is directly from the Ducksters website.  It simplifies the meaning of a mixture by breaking it down into types of mixtures mentioned in the studyjams video. 

As a class, we read and highlight main ideas in the passage.  Then I direct students to their interactive notebook and have them note these types of mixtures in a diagram format I post on the board.

 defining mixture

It is a replica similar to the one in the reading. 

Identifying Our Mixture Models

Once we identify types of mixtures, I have them return to their chart in their interactive notebook.  I have them label their each model they illustrated as either a heterogenous mixture or homogeneous mixture.  I notice they easily identify the cup 1 as a heterogenous mixture and cup 3 as a homogeneous mixture.  They are perplexed for cup 2 (oil, water, food coloring).  We refer back to the diagram defining the differences and enter into a discussion that mixtures are not always in the form of a solid and that they can be liquid and even gas form.  I share with them that air is a homogenous mixture of gases- mostly of carbon dioxide, nitrogen, oxygen, and others. I explain that if it wasn't homogenous, it would be difficult to breathe because oxygen would not dispersed throughout the air and would only be in certain areas of the world. I tell them that it would be difficult because people would only live in certain parts of the Earth which would cause impact life in general between overcrowding and food sources. 

They determine that the cup 2 (oil, water, food coloring) is a heterogeneous mixture.

Elaborate

20 minutes

Brainstorm Ways to Separate a Mixture

Since we defined mixtures can be separated, I ask the students to do a turn and talk brainstorm ways of separating the mixtures we created in our three models. After a few minutes, I ask groups to share their ideas and list them on the board.  These ideas include using a filter, a strainer, evaporation, and boiling. Then I ask, will all of these ideas work for each container?  Students agree these ideas only work on certain mixtures. They say it depends on the size of the substances that we are trying to separate. After a brief discussion on ideas, I tell the students they are going to attempt to separate each mixture 

Separating Our Mixture Models

I ask the material managers to retrieve a tray from the supply table. I point out that each tray contains the following tools: a coffee filter, a strainer, a tweezer, a spoon, and a wand(magnetic).  I don't tell the students it is magnetic as I want to them to discover that the unknown substance we added to one of our mixtures has magnetic properties. I give them time to discuss how they are going to separate the substances in each container. When they are ready, I tell them to begin.

I walk around to each group and make note of how they are separating the substances. 

Container #1:  seeds, rice, sand, iron fillings.

For this container, I notice most students begin with a strainer. They pour mixture in into the strainer and only the salt and iron the salt and iron fillings fall through.  Once they have the larger items, rice and seeds, I observe some students using their hands to separate the seeds from the rice, while others are using the tweezers to carefully pick out each grain of rice.  After separating the larger items, students return to the remaining mixture of sand and iron fillings.  I see a group trying to use the tweezers again to take apart the mixture, while another groups asks me if they can add water to the remaining mixture. I ask them to further explain their thinking behind this idea. They tell me they want to create a filter system system. They tell me the sand will be absorbed into the water because it is very small, whereas the unknown substance is too big to pass through the filter so it will stay in it.  I ask them about getting the sand out water. They ask to if they can leave the container out overnight to let the water evaporate. I tell them to go for it.

Another group discovers the wand is magnetic so they decide to try and separate the iron-fillings from the sand.  They are amazed at what is happening and very excited.

While others caught on to the magnetic wand, I pointed out to the students the group that created a filter system also had the right idea.  Their idea is accurate too.  I note that one method is faster than the other, but both processes work in separating the matter.

Container #2: oil, water, food coloring

When groups moved onto this container, I noticed they had struggles with getting started so I reconvened the class as a whole for a guided inquiry.  I asked them to think about the properties of the substances in the mixture. They come up with wet, liquid, and oil is slippery. I continue and explain that oil is lighter than water, meaning water is denser or heavier than the oil which causes the oil to float.  Water molecules are more attracted to each other than the oil molecules.

Now I have students examine their tools on the tray.  Let's think about how the density of water and oil makes it easier for us to separate it.  We notice the water is at the bottom and the oil is at the top. I pose the question, "How can we use they way it settled to separate the parts?"  I direct them to their materials tray and tell them to look for a tool that could help us.  I want them to locate the spoon.  The spoon can be used to skim the oil of the top to remove it from this mixture.

Students start using the spoon and attempt to separate the mixture. I hear some groups note that this process will take a long time. I tell the class the idea is to prove that our models can be separated which makes it an example of a mixture.

Container #3: water and kool-aid powder

Finally, students turn their attention to this container. Many suggest the process of evaporation to separate the substances.  They recall this process from out water cycle lesson earlier in the year. Once group suggest this, I ask them how we could do this. Students share that heat is needed so we could use a stove to make it happen quickly or we could leave it out over a few days to just let it happen.  We leave the mixture by the windowsill for a few days and notice the water only has evaporated and the color powder is left behind.


Real World Application

I ask the class, "Why would we need to know how to separate mixtures?"  

I guide them into thinking about pollution, oil spills in the ocean, and making clean water.  I also tell them we can remove substances like iron or minerals from the Earth to use them want them in everyday life.

 

Evaluate/Exit

5 minutes

Reflecting On What We Learned

Before leaving class, I hand out an 3-2-1 exit slip ticket. On this exit ticket, I ask students to name 3 ways to separate a mixture,  identify and describe 2 types of mixtures, and 1 kind of mixture that is part of their own life.

I selected a 3-2-1 ticket to give students a chance to note the main ideas within the lesson-mixtures and separating them. I ended this ticket with a question relevant to their own life.  This way they can start connecting the concept to everyday life.

I collect the ticket and use it as a formative assessment on this lesson.

 

student sample exit ticket